16-cell Versus Blastocyst for Embryo Transfer. Witch Is Better? S.C. Lee, D.M. Min, R.S. Ryu, Y.C. Park, C.K. Park, J.H. Kim
It will be presented at the 55th Annual Meeting of the American Society of
Reproductive Medicine in Toronto, Canada, September 25th to 29th, 1999
16-cell Versus Blastocyst for Embryo Transfer. Witch Is Better?
1S.C. Lee, 1D.M. Min, 1R.S. Ryu, 1Y.C. Park, 2C.K. Park, 1J.H. Kim
1Institute of Human Infertility and Genetics, Saewha Women's Clinic,
Pusan, Korea
2Department of Animal Science College of Animal Agriculture
Kangwon University, Chunchon, Korea
Objectives: Many reports exist about embryo transfer of early cleavage
stage through to the blastocyst stage in in vitro culture in other to
increase pregnancy rate. However, no clear information is available
regarding the effects of stage in in vitro culture on pregnancy rate.
Therefore, the purpose of this study was to evaluate whether embryo stage
in in vitro culture affects pregnancy rate.
Design: Retrospective case study utilizing records of pregnancy rate.
Analysis of 16-cell (day 4; 75∼80 hours post-insemination) versus
blastocyst (day 5; 120∼125 hours post-insemination) embryo transferred.
Materials and Methods: The subjects consisted of 161 embryo transfer (ET)
cycles under the age of forty from January 1996 to December 1997 who
underwent ET in Saewha Women's Clinic IVF Center. Medium for in vitro
culture was modified Tyrode's solution (mTLP) without glucose, phosphate
and phenol red. This medium was essentially the same as that used by Kim
et al., (1993). There were no other differences between the culture
condition for these two years. Pregnancy were defined as clinical
pregnancy when fetal heat beating were confirmed and ongoing pregnancy
when pregnancy persist more than 16 weeks. kata analyzed by chi-square
method.
Results: 첨부파일
Conclusions: Much higher pregnancy rat after IVF-ET observed in 16-cell
stage than blastocyst stage reveals that implantation of embryos
transferred from in vitro culture take place much easily in 16-cell stage.
It is known that embryo before blastocyst stage is found in oviduct and
blastocyst stage is found only in uterus. Owing to above results embryo
before blastocyst stage, 16-cell stage, is strongly recommend to
transferred in uterus in other to increase pregnancy rate.
Reference: Kim JH, Niwa K, Lim JM, Okuda K. (1993) Effects of phosphate,
energy substrates, and amino acids on development of in vitro-matured, in
vitro-fetilized bovine oocytes in a chemically defined, protein-free
culture medium. Biol. Reprod. 48:1320-1325.